PutObjectCommand from aws-sdk v3 returns empty response

Question

I am creating a simple function that uploads a single file which is less than 5 GB to AWS S3 bucket. The function neither returns any data nor error. It just returns an empty response.

The code is as follows,

const csvUploadParams = {
  Bucket: Bucketname,
  Key: fileName + ".csv",
  Body: "",
  ContentType: "text/csv"
};
let response = new Promise(async (resolve, reject) => {
  console.log("Inside the response block"); //gets invoked
  try{
    console.log("Inside the try block of response"); // gets invoked
    const csvParam = new PutObjectCommand(csvUploadParams);
    await s3.send(csvParam,function(err,data){
      if(err){
        console.log("Error in uploding file", err); // not invoked
        reject(err);
      } else{
        console.log("Response obtained", JSON.stringify(data));//not invoked
        resolve(data);
      }
    });
  } catch(err){
    console.log("Error in uploading to S3 bucket", err); // not invoked
    throw err;
  }
});
console.log("CSV Upload params : ", csvUploadParams); // this line prints empty response

Please provide any guidance on why empty response is provided.

Answer 1

You are doing a strange mix of callbacks, promises and even use an async function as argument to new Promise which never makes sense.

s3.send already returns a promise (which is probably why the code doesn't work - I don't know if it would even accept a callback, but if it does, it may not invoke it if it sees it's being awaited (which internally calls .then)).

Consider this simplified code:

const csvUploadParams = {
  Bucket: Bucketname,
  Key: fileName + ".csv",
  Body: "",
  ContentType: "text/csv"
};

try {
  const csvParam = new PutObjectCommand(csvUploadParams);
  const data = await s3.send(csvParam);
  console.log("Response obtained", data);
} catch (err) {
  console.error("Error in uploading to S3 bucket", err);
  throw err;
}